Trim ends from bok choy and discard, then chop and rinse stalks and leaves in a bowl of water.Heat oils in a skillet over medium heat. Add ginger, chili flakes, garlic, and scallion and cook for about 4 minutes, stirring to avoid sticking.Turn off heat. Add bok choy and soy sauce and steam until tender but still al dente, about 2-4 minutes.Serves about 6